Walmart announced Friday that it will partner with Uber and Lyft for grocery delivery tests beginning in Denver and Phoenix. It has also quietly been testing same-day delivery via Deliv with some members of its Sam’s Club in Miami.

During the test, Walmart employees will pack orders for pickup by the two ride-hailing services, as they already do for Walmart’s expanding grocery pickup option. Customers will pay a delivery fee (between $7 and $10) through the Walmart website–they will not need to use the Uber or Lyft app.

On-demand grocery service Instacart provides a similar service for partners such as Whole Foods, but in that case Instacart employees pack the groceries.

At the beginning of this decade, Walmart’s virtual store was playing catch-up with e-commerce giants such as Amazon. Now, as the retail behemoth competes with a new iteration of these businesses–one that is hyper-focused on convenience–these partnerships offer one way to keep pace. The company already offers grocery home delivery services in San Jose and Denver, but Uber and Lyft offer another way to expand without building a new base of couriers.

Lyft’s participation in the partnership is somewhat surprising. Uber has a division, UberRush, dedicated to powering delivery, but Lyft has said it would rather focus on ride hailing. Meanwhile, Instacart and on-demand delivery company Postmates, whose partners include Starbucks, Apple, and Walgreens, won’t be part of the test.SK